'''
# yun suan fu
print(3 + 5)    # 8
print(8 - 5)    # 3
print(3 * 5)    # 15
print(8 / 4)    # 2.0
print(8 % 5)    # 3
print(8 // 5)   # 1
print(5 ** 3)   # 125

print(3 > 1, 1 > 3)
print(1 < 3, 3 < 1)
print(3 >= 1, 1 >= 3)
print(1 <= 3, 3 <= 1)
print(3 == 3)
print(3 == '3', 3 != '3')
#print('3' > 1)

print('a' > 'b')
print("C" > '0')

age = 23
print(age >= 18 and age <=60)
print(18 <= age <= 60)
print(age >= 70 or age <= 12)
print(not age == 23)
print(not True)
print(not False)
print(age > 60 or age < 18)
print(not 18 <= age <= 60 )
'''

total = 35
total = total - 5
total -= 5
total += 5
print(total)

i = 0
i = i + 1
i += 1
i -= 1
i *= 2
i /= 2
print(i)

print('hello' in 'hello world')
print('hll' in 'hello world')
print('a' not in 'hello world')
print('e' not in 'hello world')

name = None
print(name, type(name))





